central heater won't shut off


Old 02-01-03, 07:48 PM
Visiting Guest
Posts: n/a
central heater won't shut off

My central heating unit will not shut off!!!! I have tried to shut it down by changing the thermostat but no luck! I tried to find the shutoff solenoid but am not sure that I have found it. I have tapped on it prior to my writing and a little later the fan shut down. It restarted when the temperature was set for it to begin to heat the house again. Now it will not do that. I suspect that I need another solenoid but I need the procedure to:
1) stop the flow of electricity to the solenoid
2) make sure that the small box ( approx 2" square) is indeed the
3) know the repair/replacement procedure to change the solenoid
4) put it back together to run again.
The unit is pretty old but I have had it checked and the report is that I may need to replace it but currently the burners are in good shape & do not emit carbon dioxide. The motor is still in good shape but does now begin to make a "groan" sort of noise to start up and suspect that I am nearing a time to replace the unit. I have slotted it by budget to be able to afford it sometime in the late spring but can't afford one at this time. Your help in this matter would be appreciated---ft
Sponsored Links
Old 02-01-03, 08:56 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 9,988
Received 9 Votes on 9 Posts
Question More info please.


I am very sorry but your description of symptoms does not use terminology that relates to the equipment you have.

Perhaps by solenoid you mean relay or do you mean gas valve.
You also give some clues that lead me to believe that you have a gas furnace.

In the interest of safety I would recommend that you call a heating specialist.
In order to offer advice on making repairs to gas equipment, some prior mechanical/electrical knowledge is adviseable, at least so we are speaking the same language.

If you are determined to continue to try and fix this yourself we need more info,
The Read-B-4 posting anouncement has some info on what we need to know.
Old 02-02-03, 09:06 AM
Visiting Guest
Posts: n/a
It sounds like you're talking about an old gas furnace? The pipng to the burners is called the gas train. Years ago, the incoming gas line was teed off into 2 separate piping configurations inside the furnace. The continuous larger line contained a shutoff valve ahead of the tee, a main burner solenoid valve and a pressure regulator. The smaller line that ran out of the bull of the tee contained a shutoff valve, a pilot burner solenoid valve, a pilot safetystat and pressure regulator. If this is indeed what you have and, the main burner solenoid is malfunctiiong, you would have to replace the gas train with a combination gas valve. A combination gas valve contains all of the shutoff, pressure regulation, safety, pilot burner and main burner functions in one device. Don't do this as a DIY project uness you have a very good grasp on what you're doing. Are you getting voltage to the main burner solenoid coil when it won't open? Maybe the circuit is open upstream like at the limit control or pilot safetystat?

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes
Ask a Question
Question Title:
Your question will be posted in: